<?php
class Timer {
	private $StartTime = 0;//程序运行开始时间
	private $StopTime  = 0;//程序运行结束时间
	private $TimeSpent = 0;//程序运行花费时间
	function start(){//程序运行开始
		$this->StartTime = microtime();
	}
	function stop(){//程序运行结束
		$this->StopTime = microtime();
	}
	function spent(){//程序运行花费的时间
		if ($this->TimeSpent) {
			return $this->TimeSpent;
		} else {
			list($StartMicro, $StartSecond) = explode(" ", $this->StartTime);
			list($StopMicro, $StopSecond) = explode(" ", $this->StopTime);
			$start = doubleval($StartMicro) + $StartSecond;
			$stop = doubleval($StopMicro) + $StopSecond;
			$this->TimeSpent = $stop - $start;
			return substr($this->TimeSpent,0,8)."秒";//返回获取到的程序运行时间差
		}
	}
}
/*$timer = new Timer();
$timer->start();
$timer->stop();
echo "程序运行时间为:".$timer->spent();*/
?>